4-Point Bending Stiffness Tester | 4PF-50

Accurate Flexural Stiffness Testing for Corrugated Board & Packaging The 4PF-50 4-Point Bending Stiffness Tester is designed to quickly and accurately measure the flexural stiffness of corrugated cardboard and board packaging in accordance with ISO 5628. Flexural stiffness is a critical property of corrugated board, influencing the structural strength, stacking performance and Box Compression Test (BCT) performance of finished packaging. The 4PF-50 applies a controlled four-point bending load while precisely measuring specimen deflection within the elastic range. With a robust, high-stiffness test frame, precision electromechanical drive and computer-controlled measurement system, the 4PF-50 provides reliable and repeatable results for quality control, laboratory testing and research & development. Key Features 1 kN maximum test force Supplied with 500 N load cell ±0.5% force accuracy (Class 0.5) 0.001 mm displacement resolution Test speeds from 0.5 to 1,000 mm/min Precision servo motor and ball-screw drive High-stiffness single-column test frame Closed-loop control of force, displacement and crosshead movement Large, accessible testing area Multiple selectable measurement units Automated test data acquisition and analysis Comprehensive test reporting and PDF generation METROTEST testing software and Mini PC included METROTEST Testing Software The included METROTEST software provides intuitive computerised control of the 4PF-50, with real-time monitoring of test parameters, graphing, data analysis and report generation. Key functions include: Automatic data acquisition and result storage Real-time force and displacement curves Automatic graph scaling and curve analysis Standard and reference curve comparison Configurable test limits Automatic specimen-by-specimen result saving Customisable test reports PDF report generation Basic statistical analysis Selection of force and deformation units Test database management Technical Specifications Specification 4PF-50 Maximum machine force 1 kN Standard load cell 500 N Force resolution 0.005 N Force accuracy ≤ ±0.5% Displacement resolution 0.001 mm Crosshead travel 500 mm Test speed range 0.5–1,000 mm/min Test speed accuracy ≤ ±1% Maximum return speed 1,000 mm/min Adapter spacing 500 mm Power supply 220 V / 50 Hz or 110 V / 60 Hz, single phase Approx. power consumption 400 W Operating temperature 10–35°C Relative humidity 20–80% Test frame dimensions Approx. 420 × 670 × 950 mm Net weight Approx. 76 kg Applications The 4PF-50 is suitable for testing: Corrugated board Cardboard boxes Corrugated packaging Board packaging materials Packaging materials used in quality control and R&D Standards The 4PF-50 is designed for testing in accordance with ISO 5628 and is also compatible with relevant requirements of ISO 7500-1, ASTM E4, EN 10002-2, BS 1610, DIN 51221 and ISO 6892. Standard Supply The standard system includes: 4PF-50 4-Point Bending Stiffness Tester 500 N load cell Four-point flexure testing fixture METROTEST multilingual testing software Mini PC with Windows operating system Test results database and basic statistical analysis package Reliable Corrugated Board Flexural Stiffness Testing The 4PF-50 combines precision force and displacement measurement with automated software control to provide a reliable solution for evaluating the bending stiffness and structural performance of corrugated board and packaging materials.